This Plane Just Circumnavigated the Globe Without a Single Drop of Fuel

After 23 days of flight and over 43,041 km travelled, the Solar Impulse 2 (Si2) has completed a historic mission, completing the world’s first, around-the-globe solar flight without using a single drop of fuel.

Piloted by Bertrand Piccard and André Borschberg, Solar Impulse 2 first embarked on the 17 leg journey from Abu Dhabi on March 9, 2015. The duo just recently completed their mission because the pilots faced a nine-month delay last year after the plane’s batteries were damaged during a flight from Japan to Hawaii. It was also delayed for more than a week in Cairo ahead of its final flight to Abu Dhabi due to poor weather conditions and Piccard falling ill.

Si2 is a single-seater aircraft made of carbon fiber that has a 72m / 236ft wingspan (larger than a Boeing 747) for a weight of 2300kg / 5100lb (the equivalent of an empty family car). The 17,248 solar cells built into the wing power the four batteries (38.5kWh per battery) that in turn power the four electric engines (13.5kW / 17.5hp each) and the propellers with renewable energy. The plane is therefore capable of saving a maximum amount of energy during the day and flying throughout the night on batteries. Si2 requires zero fuel and has virtually unlimited autonomy: theoretically, Si2 could fly forever and is only limited by the pilot’s sustainability.

A total of 19 world records were set or are still pending by the World Air Sports Federation (FAI), in particular when André Borschberg accomplished the pioneering first of flying five consecutive days and nights over the Pacific Ocean from Japan to Hawaii in the longest duration a solo airplane of any kind has ever flown and when Bertrand Piccard achieved the historic first crossing of the Atlantic Ocean in a solar airplane. It took Piccard 70 hours.

Solar Impluse 2 completed more than 500 flight hours, cruising at an average speed between 28 mph (45 kmh) and 56 mph (90 kmh). It made stops in Oman, India, Myanmar, China, Japan, the U.S., Spain, Italy, Egypt and the United Arab Emirates. Its North American stops included California, Arizona, Oklahoma, Ohio, Pennsylvania and New York. [source]

The pilots would rest a maximum of 20 minutes at a time, repeating the naps 12 times over each 24-hour stretch. Neither pilot was able to stand in the cockpit while flying, but the seat reclined for stretching and its cushion could be removed for access to a toilet. Goggles worn over the pilot’s eyes flashed lights to wake him up while armbands placed underneath their suits buzzed when the plane was not at flying level. [source]

Piccard, a psychiatrist, is the son of undersea explorer Jacques Piccard and a grandson of balloonist Auguste Piccard. In 1999, he became the first person to circumnavigate the globe non-stop in a hot air balloon. Borschberg, an engineer and graduate of Massachusetts Institute of Technology, is also an entrepreneur. He launched the Solar Impulse project in 2003 with Piccard. [source]